transport in animals

Question 1

what is a single circulatory system

Answer 1

blood flows through the heart once for each circuit of body

Question 2

what’s a double circulatory system

Answer 2

blood flows through heart twice for each circuit of body

Question 3

what are features of a good transport system

Answer 3

-A fluid or medium to carry nutrients
-A pump to create pressure to push fluid
-Exchange surfaces
-Tubes or vessels to carry blood
-Two circuits

Question 4

what are properties of arteries

Answer 4

-carry blood away from the heart
-blood at high pressure so thick elastic walls to withstand pressure
-small lumen to maintain high pressure
-has layers: tunica intima, tunica media and tunica adventitia
-blood flows into artérioles

Question 5

what are the 3 layers in arteries

Answer 5

-tunica intima
-tunica media
-tunica adventitia

Question 6

what are properties of veins

Answer 6

-carry blood back to heart
-blood at low pressure
-thin walls
-large lumen
-collagen and smooth muscle in walls
-contain valves to stop back flow of blood

Question 7

what are in the walls of veins

Answer 7

collagen and smooth muscle

Question 8

what are properties of capillaries

Answer 8

-walls one cell thick for gas exchange
-walls leaky (fenestrations)
-narrow lumen-increases resistance and reduces rate of flow
-blood flows into venules

Question 9

what are fenestrations in capillaries

Answer 9

tiny openings or pores

Question 10

where does the blood flow from capillaries

Answer 10

venules

Question 11

where does the blood flow from arteries

Answer 11

into arterioles

Question 12

process of exchange at capillaries

Answer 12

-blood enters capillary at artériole end with a high hydrostatic pressure
-high pressure forces plasma out of holes in capillary wall which forms tissue fluid
-tissue fluid contains oxygen, glucose or anything small enough to fit through holes
-red blood cells, large proteins and some white blood cells remain in capillary
-exchange occurs between tissue fluid and cells
-tissue fluid rich in CO2 and waste moves back into the venule end of the capillary due to low hydrostatic pressure in the capillary

Question 13

how does size effect transport systems

Answer 13

-cells inside large organisms are further from surface so diffusion pathway increases
-reduces diffusion
-the outer cells would use up the supplies and inner cells would be deprived

Question 14

how does surface area to volume ratio effect transport systems

Answer 14

-small animals have a large surface area to vol ratio
-this means that each tissue in their body has a sufficient area for exchange to occur

-larger animals have a smaller surface area to volume ratio
-this means that each tissue has a smaller area of body for exchange to happen

Question 15

how does level of metabolic activity effect transport systems

Answer 15

-more active animals need good supplies of nutrients and oxygen to supply energy for movement
-same applies for animals that want to keep warm

Question 16

what are advantages of a double circulation in mammals

Answer 16

increased efficiency in oxygen and nutrient delivery to tissues. It keeps oxygenated and deoxygenated blood separate,

Question 17

example of a single circulatory system animal

Answer 17

fish

Question 18

example of double circulatory system in animals

Answer 18

mammals

Question 19

what is hydrostatic pressure

Answer 19

pressure in a vessel

Question 20

what is oncotic pressure

Answer 20

pressure created by the presence of solutes

Question 21

what is tissue fluid

Answer 21

formed by plasma leaking from the capillariesw

Question 22

what does tissue fluid do

Answer 22

surrounds the cells in the tissue and supplies them with the oxygen and nutrients they need

Question 23

how does substances dissolve into the tissue fluid

Answer 23

as blood plasma leaks from the capillary it carries dissolved substances into the tissue fluid

Question 24

what is the movement of substances leaking from capillary to tissue fluid

Answer 24

mass flow

Question 25

what are the molecules that are too large to be forced out of the tiny gaps in capillaries

Answer 25

-red blood cells -platelets -large proteins

Question 26

what is the effect of large molecules remaining in the capillaries

Answer 26

create a lowered water potential

Question 27

what is teh pressure like towards the venule end of capillaries

Answer 27

the hydrostatic pressure is lowered

Question 28

why is the hydrostatic pressure towards the venule end lowered

Answer 28

due to the loss of liquid, but the water potential is very low

Question 29

how does water re enter the capillaries

Answer 29

by osmosis

Question 30

what happens to the liquid tissue fluid that doesnt get reabsorbed

Answer 30

the rest of the tissue fluid absorbed into the lymphatic system and eventually drains back into the bloodstream near the heart

Question 31

what does blood do when theres negative oncotic pressure

Answer 31

move into blood

Question 32

what does blood do when theres positive oncotic pressure

Answer 32

move out of the blood

Question 33

relate the structure of arteriolar and venules to their function

Answer 33

-branch off arteries and veins in order to feed blood into capillaries -smaller then arteries and veins so that the change in pressure is more gradual as blood passes through increasingly small vessels

Question 34

how does tissue fluid form

Answer 34

as blood is pumped through small vessels, hydrostatic pressure is greater than oncotic pressure so fluid moves out of the capillaries. it then exchanged substances with the cells

Question 35

what does an increase in conc of glucose in the blood do to the water potential in the blood

Answer 35

decreases is